Electromagnet.



PATENTED AUG. 13, 1907.

D. L. LINDQUIST. ELEOTROMAGNBT.

APPLICATION FILED MAY 9, 1906.

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omma of LettersjPatent.

Patented Aug. 13, 1907.

Application filed'May 9,1905 Serial No. 259,552.

To all whom it may concern:

Be itknown that I, DAVID LEONARD LINnQUIsT, oi Yonkers, Westchester county', New York, have invented a new and useful Improvement in Electromagnets, of

which the following is a specification.

The invention relates to an electro-magnet operable .by a. varying current: and more particularly by an alternating current of electricity.

The invention has for its objectto prevent the chattering noise due to vibrations of the armature against a fixed abutment and resulting from the varying current in the magnet coil.

The principle of the invention consists in initially varying the attractive forceof the magnet, equilibrating the modified force mechanically and taking up the vibrations due to current variations by suitable means.

The invention consists in the combinations and instrumentalities more particularly pointed out in the claims.

the nut H, whereby the circuit terminal I is secured to it. The opposing contact plate I is carried by a threaded rod .I which passes loosely through a plate K of insulating material and through the upper end of armature E. On rod .l and received in a recess in the armature is an adjusting nut L, and between contact plate I and insulating plate K is interposed a helical spring M, the tension of which spring may be varied by means of nut L. On rod J outside of nut L is a clamp nut N,

I by means of which a circuit terminal 0 is secured to said rod. When plate I makes contact with plate 'F circuit is established between terminals 0, P. The magnet coil is to be connected to any suitable source of alternating current, as symbolically indicated at Q.

It will be apparent that when the magnet is energized a compound magnetic circuit exists through core, armature, and an air gap between armature and magnet pole. The width of said gap determines the magnetic resistance in the circuit and may be regulated by means of the nut L, which moves the plate I nearer to or further from the fixed insulating plate K. Thus, if

the plate I be moved nearer to plate K, the air gap will be diminished when circuit closing contact is made be tween plates I and F, and when plate I is moved further from plate K the air gap will be increased when such contact is made. But the movement'of plate I also controls the tension of helical spring M, with the result that as the resistance in the magnetic circuit is decreased the tension of the spring is increased and vice versa. I thus esablish an initial relation between the resistance in the magnetic circuit and the spring tension; or in other Words, I am enabled by suitably operating the nut L to secure, when the plates I and F are in contact, a certain width of air gap and a certain tension of spring. i In this way I initially equilibrate the attractive force of the magnet due to its energizing current against the resilience of the spring. The variations or alternations of the current after this equilibration is effected are also taken up by the spring. The armature being loose on the rod .I and the contact plate I forming a head on said rod, being against the abutment provided by the fixed plate F, it follows that the vibrations of the armature become directly transmitted to said spring, and are thus prevented from effecting separations and. chattering between contact plates I, F.

1. A source of alternating; current, an electro nngnet energized thereby, a movable armature in magnetic circult with the core of said magnet, means for adjusting the resistance of said magnetic circuit, and menus for equilibrating theresultlng' attractive force of said magnet upon said armature, and for talking up the vibrations of said armature due -to current alternations.

A source of alternating current, an electro-niagnet energized thereby, a movable armature in magnetic circuit with the core of said magnet, means for adjusting the resistance of said magnetic circuit, and means for eqnllibrating the resulting attractive force of said mag net upon said armature.

A source of alternating current, an electroina ;netv

energized thereby, a movable armature in magnetic circuit with the core of said magnet, means tor eqnilibrating the resulting attractive force of said magnet upon said armature and means for simultaneously adjusting said equilibrnting means and the resistance of said magnetic circuit.

4. A source of alternating current, an electro-nm giot energized thereby. a movable armature in magnetic circuit with and separated by an air gap from the core of said magnet, a spring constructed to oppose the motion of said armature, and means for simultaneously adjusting the width of said air gap, and the tension of said spring.

5. A source of alternating current. an elcctroqnagnet energized thereby, a pivoted armature in magnetic cir-' cult with and separated by an air gap from the core of said magnet, a rod loosely passing through said armature, a spring interposed between an abutment on said rod and said armature, a fixed abutment in the path of movement of the said rod. and means for adjusting the tension of said spring.

3. A source of iilternntingwurrent, :i n electro-magnet' energized thereby. a pivoted armature in magnetic circuit with and separated by :in air gap from'the core of said magnet, a threaded rod loosely passing through said armature, a spring interposed between an abntme nt on said rod and said aimature, a nut 'on said rod for adjustspecification in the presence of two subscribing witnesses.

DAVID LEONARD LIXDQTY I ST.

Witnesses:

/ PARK BExJAM x, Jr.,

JANET A. Gnnxmxxms. 

